It is suggested that the valence-band structure observed in x-ray photoemission from certain insulating $3d^n$ compounds can be identified with the crystal-field states of the $3d^{n-1\mathrm{}}$ final state.

Recoilless-absorption measurements of the 21.6-keV $\gamma$ ray of ${\mathrm{Eu}}^{151}$ in Eu${\mathrm{Cu}}_2$${\mathrm{Si}}_2$ reveal an absorption line which has a strongly temperature-dependent isomer shift. The lines fall at neither the ${\mathrm{Eu}}^{3+}$ nor the ${\mathrm{Eu}}^{2+}$ valence positions, but in between. The results are interpreted in terms of fast fluctuations ($\tau <3.5\mathrm{}\times {10}^{-11\mathrm{}}$ sec) of an electron between the localized $4f$ level and the conduction band. The difference in energy between the ${\mathrm{Eu}}^{2+}$ and the ${\mathrm{Eu}}^{3+}$ states in Eu${\mathrm{Cu}}_2$${\mathrm{Si}}_2$ is found to be about 0.07 eV.

We show that, in nearly magnetic metals, taking into account the temperature dependence of the Stoner susceptibility makes the electron-paramagnon electrical resistivity depart from the usual low-temperature $T^2$ and $T$ power laws at temperatures higher than the spin-fluctuation one. A high-temperature plateau is expected and a maximum may arise at lower temperature depending on the parameters. Possible fits are presented for the resistivities of Pu and Np.

Normal-incidence reflectivity measurements between 0.5 and 6 eV on thorium metal reveal the existence of bandlike (or itinerant) $f$ states several electron volts above the Fermi energy. The predictions of relativistic band-structure determinations are in qualitative agreement with experiment. This study provides the first direct observation and characterization of $5f$ electrons in metals as being itinerant in nature and unlike the $4f$ states in the rare earths.

Polarized ${\mu }^{+}$ were stopped in Ni and Fe. The magnetic fields at the site of the muons, the initial polarization, and the depolarization time constant were obtained from 300 to 700°K, i.e., through the Curie temperature of Ni. This experiment demonstrated that precession of muons stopped in ferromagnetic material can be observed and, and it determined what the magnitude of the internal fields are: $\approx 150$ G for Ni and 4000 G for Fe.

The giant-resonance region in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ was observed by inelastic electron scattering. We present evidence for the existences of a $2^{+}$ (or $0^{+}$) state at ∼ 22 MeV and a $3^{-}$ state at ∼ 19 MeV with giant-resonance character. The resonance states between 8.6 and 11.6 MeV are confirmed to be $2^{+}$ (or $0^{+}$) and the sum of their strengths exhausts about 50% of the $E2\mathrm{}$ sum rule or 100% of $E0\mathrm{}$.

Elastic pion-nucleus scattering is treated using a separation in Hilbert space via a projection-operator formalism. The basic assumption is that the elastic scattering and reactions due to the $\pi -N$ resonance proceed through doorway states consisting of a $\Delta \mathrm{}\left(1236\right)\mathrm{}$ resonance in the nucleus. Nonresonant scattering and absorption processes are included by background terms, which are approximately known. The formalism is applied to ${\pi }^{-}-{}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ scattering.

Data are presented for single-proton transfer reactions induced by ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ ions on ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ at high bombarding energies. Analysis using a no-recoil distorted-wave Born approximation (DWBA) yields spectroscopic factors in marked disagreement with lightion results. Analysis using DWBA theory including first-order recoil corrections indicates that the discrepancies are largely, if not entirely, the result of ignoring recoil effects.

Differential cross sections are measured for ${}_{}{}^{58,60,62,64}{}_{}{}^{}\mathrm{Ni}$(${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$) reactions to both ground and excited ($2^{+}$) states of the residual Ni nuclei at incident ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ laboratory energies of 65, 57, and 50 MeV. Anomalous, forward-rising, angular distributions are seen for ${}_{}{}^{58,60}{}_{}{}^{}\mathrm{Ni}$(${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$) reactions, in contrast to normal heavy-ion-induced transfer shapes obtained for the heavier Ni targets. A theoretical explanation is presented based on a weaker absorption than is usually employed for such heavy-ion transfer reactions.

Models of differentially rotating neutron stars have been calculated. An upper limit to the rotational enhancement of the maximum gravitational mass is found to be about 50% when the Ostriker-Tassoul instability criterion is used.

Presented here are preliminary results of two short runs with a broad-band neutrino-antineutrino beam at National Accelerator Laboratory incident on about 120 tons of target which is part of a detector consisting of an ionization calorimeter and a muon magnetic spectrometer. These results include (i) the observed distribution in transverse muon momentum, $\frac{\mathrm{dN}}{d{p}_{\mu }}$, (ii) the average neutrino cross section at a mean neutrino energy of roughly 30 GeV, and (iii) the ratio of the antineutrino to the neutrino total cross section at a mean neutrino energy of 40 GeV.

Cross sections for inelastic scattering of electrons from hydrogen and deuterium were measured for incident energies from 4.5 to 18 GeV, at scattering angles of 18°, 26°, and 34°, and covering a range of squared four-momentum transfers up to $20 {\left(\frac{\mathrm{GeV}}{c}\right)}^2$. Neutron cross sections were extracted from the deuterium data using an impulse approximation. Comparisons with the proton measurements show significant differences between the neutron and proton cross sections.

The ratio $\frac{(\overline{p}d\to {\pi }^{-}{\pi }^0{p}_s)}{(\overline{p}d\to {\pi }^{-}{\pi }^{+}n)}$ at rest, with spectator momenta $\lesssim 300 \frac{\mathrm{MeV}}{c}$, has been measured and found to be 0.68 ± 0.07. This implies that (75 ± 8)% of the annihilations in deuterium into two pions come from odd $\overline{N}N$ orbital angular momenta, in disagreement with the $S$-state-dominance hypothesis. It has also been observed that the $\overline{p}d\to {\pi }^{-}{\pi }^0{p}_s$ production rate depends on the spectator momentum, which suggests energy-sensitive $\overline{N}N$ phenomena near threshold.

For any unitary theory in which the average multiplicity grows slower than any small positive power of $s$, and in which the Regge-type asymptotic behaviors ${\sigma }_{\mathrm{tot}}\mathrm{}\left(s\right)\mathrm{}\sim s^{{\alpha }_{\mathrm{P}}\mathrm{}\left(0\right)-1\mathrm{}}$ and ${\sigma }_{\mathrm{e}1}\mathrm{}\left(s\right)\mathrm{}\sim s^{2{\alpha }_{\mathrm{P}}\mathrm{}\left(0\right)-2\mathrm{}}$ hold, modulo powers of $\ln \mathrm{}\left(s\right)\mathrm{}$ for both, I derive a simple, necessary and sufficient condition which guarantees that ${\alpha }_{\mathrm{P}}\mathrm{}\left(0\right)=1\mathrm{}$. The condition is ${max}_n{\sigma }_n\le C{\sigma }_{\mathrm{e}1}{s}^{\epsilon }$ for arbitrarily small $\epsilon >0\mathrm{}$ and large enough $s$, where ${\sigma }_n$ is the actual cross section for producing $n$ hadrons in the final state, ${\sigma }_{\mathrm{e}1}$ is the total integrated elastic cross section, and $C$ is independent of $\epsilon$.

We report the results of a high-statistics scintillation-counter electronics experiment measuring the muon polarization in the decay ${K_L}^0\to {\pi }^{-}{\mu }^{+}{\nu }_{\mu }$ by the method of spin precession. We present results for the real and the imaginary parts of the form-factor ratio.

We report here the results of a statistical cross-correlation study between 262 of Weber's gravitational radiation events and various geophysical, meteorological, and other phenomena. A correlation at the 2.7 standard-deviation level is found between the gravitational radiation events and the measure of the magnetospheric ring-current intensity, and at the 3.0 standard-deviation level with sidereal time. The results imply that some of the reported gravity events could be caused by processes other than gravitational radiation.

The differential cross section for ${\pi }^{+}p$ elastic scattering has been measured at $13.8 \frac{\mathrm{GeV}}{c}$ for $0.7<\mathrm{}\left|t\right|<3.8\mathrm{}{\left(\frac{\mathrm{GeV}}{c}\right)}^2$. The cross section is found to be equal to that previously obtained for ${\pi }^{-}p$ elastic scattering, except in the region $\mathrm{}\left|t\right|=2.8\mathrm{} {\left(\frac{\mathrm{GeV}}{c}\right)}^2$, where the ${\pi }^{+}p$ data do not show the prominent dip observed in ${\pi }^{-}p$ scattering. Data have also been obtained for $13.8-\frac{\mathrm{GeV}}{c} K^{+}p$ elastic scattering for $0.8<\mathrm{}\left|t\right|<2.2\mathrm{} {\left(\frac{\mathrm{GeV}}{c}\right)}^2$.

It is shown that in a rearrangement collision leading to the formation of highly excited hydrogenlike states the cross section at high energies behaves as $\frac{1}{n^2}$, with $n$ the principal quantum number, thus invalidating the Brinkman-Kramers approximation for large $n$. Similarly, in high-energy inelastic electron-hydrogenlike-atom collisions the exchange cross section for sufficiently large $n$ dominates the direct excitation cross section.

The first members of the hydrogen line series with lower states $n=10,11,12, \mathrm{and} 13$ have been detected in a laboratory plasma. The width of the $12-\alpha$ line at 88.7 μm could be measured and was consistent with calculated broadening from elastic electron collisions and quasistatic ion effects.

We report observation of hyperfine quantum beats in the light emitted by the $7{{}_{}{}^2{}_{}{}^{}P}_{\frac{3}{2}}$ level of ${\mathrm{Cs}}^{133}$ after excitation by a short resonant dye laser pulse. Frequency analysis of the beats provides a measurement of the hyperfine splittings in agreement with previous work. The usefulness of quantum-beat detection as a new method of laser spectroscopy without complications from the Doppler effect is discussed.